Barium titanate-based semiconductor materials are widely known as semiconductor ceramic materials with a positive temperature coefficient of resistance. Such semiconductor materials sharply increase in resistance at temperatures not lower than their Curie temperatures, that is, such semiconductor materials feature a PTC (positive temperature coefficient of resistance) and therefore are used for constant-temperature heaters, temperature sensors, and PTC thermistors for overcurrent protection.
Patent Literature 1 discloses a barium titanate-based semiconductor ceramic composition represented by the formula (Ba(1-v-w)SrvErw)TixO3+yMn+zSiO2, wherein v is 0.05 mol to 0.40 mol, w is 0.005 mol to 0.012 mol, x is 1.00 mol to 1.04 mol, y is 0.0004 mol to 0.0018 mol, and z is 0.01 mol to 0.04 mol.
As described in Patent Literature 1, a barium titanate-based semiconductor ceramic composition having low resistivity at room temperature, a large temperature coefficient of resistance, and high breakdown voltage is obtained.